Powered prostheses have the potential to improve the walking ability of individuals with transfemoral amputations. However, propulsion of the swing movement is generated entirely by the user, who must pull the thigh forward at the end of stance (i.e., exaggerating the hip flexion torque) to initiate the swing movement. This unnatural action produces an asymmetric gait pattern. Powered prostheses can overcome this limitation by mimicking the action of biological muscles to actively propel and control swing movement. However, attaining biologically accurate swing requires continuous adaptation of swing movement duration with walking speed and cadence. Many powered transfemoral prostheses largely rely on impedance-inspired control, an approach that does not allow direct regulation of swing duration. Impedance inspired control defines joint torque as a parametric function of angle and velocity, with different stiffness, damping, and equilibrium values for each discrete phase of the gait cycle. Swing duration therefore depends on the dynamic interaction of the prosthetic leg with the user and the environment during the swing phase, as well as on leg angle and velocity at the transition between stance and swing phase. Swing trajectory can be modified by regulating the impedance parameters of the prosthesis, though swing duration cannot be defined a priori (i.e., it is not a controlled parameter). Because impedance-inspired control needs user and speed-specific tuning to obtain desired swing duration, variable cadence can be difficult to achieve.